The following is a list of some of the more general strategies in the game of chess. Obviously, such a list is not even close to exhaustive, and entire books are devoted to some of these themes by themselves.
Controlling the center of the board
The center of the board is the most important area to control. In general, players with control over the central squares can launch successful attacks or place their opponents in a bind. Traditionally this is achieved through placing pawns in central locations (d4 or e4 for white). However modern play beginning with Nimzovitch has shown this can also be achieved with pieces.
The more squares a player controls, the more options his pieces have. One way to evaluate the amount of space, or squares available to a player, is to compare the number of squares attacked by his pieces and his opponents'. Effective use of pawns to deny good outposts for the opposing pieces while creating good squares for friendly pieces is often a key strategic goal.
Outposts and Open files
A related concept to spatial control is that of outposts and open files. An open file is one in which there are none of your own pawns. It is strong because it means the heavy pieces (rooks and the queen) can control the file from the safety of distance. Placing both Rooks together on a rank or file with no pieces in between is a powerful method of attack because each rook defends the other. An outpost is a position of strength for a knight and is defined as square on an open file, protected by a pawn and immediately in front of an opponents pawn. A knight on this square can impose much pressure on the opponent and is immune to immediate attack unless the opponent weakens their pawn structure.
A player is advised to move all his pieces from their original position in order to bring them into use in the game. A common way to gain an advantage in time is to develop (i.e., move out from the starting positions) pieces and pawns before the opponent does. If one player manages to start an attack with all of his pieces before his opponent can get his pieces into the game, the attacker is effectively playing a piece or two ahead.
Tempo is a concept in the opening meaning that a player has made more effective moves than his opponent. A player can gain an advantage in tempo by efficiently involving and coordinating all of his pieces. Tempo can also be achieved by making moves that have multiple consequences for the opponent. For instance, a developing move that also threatens an opponents' piece leads to a gain in tempo when the opponent is forced to defend his piece without a gain in development. Another common method of achieving tempo is through the sacrifice of a pawn in the opening and exploiting the opponents attempts to maintain the advantage. In general, in the opening, a pawn is the equivalent of 2 tempi.
As the King's capture means the loss of the game, protecting the King is paramount. For this reason, it is recommended to castle in virtually every game. Castling provides the King with a shield of pawns and shuttles it to the side of the board, where it is relatively safe. Castling also enables the rook to be released, and used for attack and defence. Preventing the opponent from being able to castle can be a very good strategy as it leads to the opposite king being exposed and vulnerable to early attack. It is also advisable to refrain from moving the pawns immediately in front of a castled king as this weakens the position and can result in outposts for the opponent.
Pawn structure, also known as pawn formation, plays an important role in chess. Players strive to maintain strong pawn structures while trying to create weaknesses for their opponents. Weak pawns can then serve as the focus for an attack. In general, weak pawns are those that are
- Isolated pawns; they don't have a pawn on either file to their sides, and are thus unable to be protected by other pawns.
- Doubled pawns; two pawns are on the same file, so that they can't defend each other. Tripled pawns (three on the same file) are even weaker.
- Backward pawns; they have not advanced as far as their fellow pawns, and thus can't be defended by them.
Jeremy Silman, a famous chess writer and coach, argues that these pawns should not be automatically considered "weak" without taking into account some of the other positional factors relating to them. For instance, if an isolated pawn is placing strong pressure on the opponent's position and cannot be easily captured, it would not be considered weak. An isolated queens pawn (pawn on the d file) is often an advantage in the middle game because it entails two open files for the heavy pieces (rooks and Queen) to use to attack.
- How to Reassess Your Chess by Jeremy Silman
- My System by Aron Nimzovitch